How to prepare to iOS 11 installation ?

In a few days (weeks ?) iOS 11 will be released, and I'm looking forward to have it installed on every iDevice I own ( iPhone 7, iPad Air 2 and iPad Mini 4, not to speak about my wife's iPhone 5S and my son's iPhone SE).
On my primary device, the iPhone 7, I have some very important apps, like password manager and home banking app, and I'm not sure if they will be completely restored (content included) with an iCloud backup.
To have a "clean" installation I'm planning to update iOS via iTunes (is that correct ?) instead of the OTA upgrade, and my question is: how to have ALL the data restored on my phone ? Is that possible ? Do I have to make an iTunes backup and restore that ?
I'm also interested in keeping my health data, collected with my Apple Watch.
Thank you for the precious help.

I'm a little worried about an OTA update for such a big change... On the other side I don't want to lose settings and app data on my iPhone. I think the iTunes encrypted backup is the only option I have in this case.